Methylene bis(dibutyldithiocarbamate)
MAK Value Documentation – Translation of the German version from 2020
Andrea Hartwig1 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
2 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated methylene bis(dibutyldithiocarbamate) [10254-57-6] considering all toxicological end points. Available publications and unpublished study reports are described in detail. In a study carried out according to OECD Test Guideline 422, increased liver weights and reduced body weight gains were observed in female rats at 375 mg/kg body weight and day with a NOAEL of 75 mg/kg body weight and day. Inhalation studies are not available for methylene bis(dibutyldithiocarbamate); however, irritation of the eyes or airways is not expected as the substance is not irritating to the skin or eyes of rabbits. The bioavailability of the substance is assumed to be almost negligible after oral and inhalation exposure because of its physico-chemical properties. Based on the NOAEL and these considerations, the maximum concentration at the workplace (MAK value) is set at 20 mg/m3 for the inhalable fraction (I). Inhalation of the inhalable fraction results in gastrointestinal exposure via mucociliary clearance, decreasing any concentration peaks. Therefore, Peak Limitation Category II with an excursion factor of 8 is established. The toxicity of the respirable fraction (R) of methylene bis(dibutyldithiocarbamate) in the lung is expected to be similar to that of severely refined mineral oil, for which a MAK value of 5 mg/m3 R has been derived on the basis of inhalation studies. Therefore, the MAK value for methylene bis(dibutyldithiocarbamate) is also set at 5 mg/m3 R. The substance is likewise assigned to Peak Limitation Category II with an excursion factor of 4 by analogy with severely refined mineral oil. Methylene bis(dibutyldithiocarbamate) does not cause foetotoxicity in rats up to an oral dose of 1500 mg/kg body weight and day; this dose is toxic to the dams. However, a teratogenicity study has not been performed on methylene bis(dibutyldithiocarbamate). As the available data are not sufficient for an evaluation, methylene bis(dibutyldithiocarbamate) is assigned to Pregnancy Risk Group D. Methylene bis(dibutyldithiocarbamate) is not genotoxic in vitro; in vivo data are not available. A carcinogenicity study has not been performed on methylene bis(dibutyldithiocarbamate). Skin contact is not expected to contribute significantly to systemic toxicity. Limited data show no sensitization.
